<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script>
        function Person(name) {
            this.name = name;
        }
        Person.prototype.print = function () {
            return this.name;
        };

        Person('abc');
        const a = new Person('abc').print.call({});
        console.log(a);//undefined

        const fn = () => {
            this.x = 'z';
        };

        const b = { x: 'y' };
        fn.call(b);
        console.log(b);//{ x: 'y' }
    </script>
</body>

</html>